Fruit-drier.



J. H. SPRAGUE.

FRUIT DRIER. APPLICATION FlL ED MAY 13- Q914- g a Patentefi June 8,1915.

lniventor I .r 7 a Attorneys ANT . FRUIT-DRIER.

Application filed May 13, 1914. Serial No. 838,342.

. To-all whom it may concern:

Be it known that I, JAMES H. SPRAGUE, a.

citizen of the United States, residin at- Clarkston, in the countyofAsotin and tate of Washington, have invented a new and usefulFruit-Drier, of which the following is a specification.

This invention relates to improvements in drying cabinets and moreparticularly to one of that type adapted to dry fruit and alliedproducts.

An object of the present invention is to provide a fruit dryingreceptacle in which 'the temperature and humidity of the air may beautomatically maintained at the requisite points, for the uniform andefficacious drying of articles disposed within the receptacle.

A further object is to provide a cabinet or receptacle includingdehydrating, heatingy and drying chambers so that a circulation of airwill be set up and maintained thus eliminating to a large degree thenecessity of introducing new or fresh air into the cabinet/which willlower the efficiency of the entire apparatus;

With the foregoing and other objects in viewwhich will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed, can be made within thescope of what is claimed, without departing from the spirit of theinvention.

In the drawings accompanying this specification and: forming a partthereof, the preferred: embodimentof my invention is illustrated, inwhich Figure 1 is-a front view in elevation of my improved dryingcabinet with portionsthereof removed so as to more clearly disclose itsinterior construction. Fi 2 is a sectional. view taken on the line 2- ofFig. 1. Fig. 3 is a fragmental view in section of the drying cabinetwith the trays rearthe cabinet.

wardly and upwardly inclined, which tends to improve the circulation of'air through Fig. 4 is a fragmental view illustrating in section thepassage between the dehydrating and drying chambers.

Referring to the drawings in which similar reference numerals designatecorresponding parts throughout the several views, the cabinet includesthe side walls S Specification of Letters-Patent.

Patented June 8, 1915.

to the lower extremities of which. isflsecured the bottom 3. A top 4 ofrelatively less width than the bottom is connected to the upperextremities of the side walls, and all of which unite in supporting thefront wall 5. The front wall is provided with thedoor 6 rendering theinterior of the cabinet accessible. A rear wall 7 oiirelatively smallsize extends between the side walls and is connected to the bottom 3.The cabinet, as so constructed will possess the required rigidity andinasmuch as the various parts mentioned are all formed ofwood, thecabinot will be insulated from external temperatures.

Secured to the wooden back 7, which it is to be noted is of relativelysmall height, is the rear plate 8 of a cooling and condensing hood,which latter includes the front'plate' l0 and the upper cylindrical orarcuate top'9. The hood is formed of relatively thin metal so that thesame will be affected by external temperatures and thus maintained at alower temperature than the remaining portions of the cabinet. Apartition 11 extends parallel to and is spaced from the metal back plate8 and which partition acting in conjunction with the inclined lowerpartition 12, defines the drying chamber 13, the cooling and condensingchamber 14, hereinafter referred to as the dehydrating chamber and theheating chamber 15. The partitions are formed of Wood or some alliedsubstance having a low coeflicient of thermal conductivity so that thevarious chambers may be maintained at different temperatures for thesuccessful working of the apparatus.

The drying chamber 13 which is rendered accessible by the door 6, isdivided into a plurality of compartments by the transversely extendingpartitions 16 each of I which partitions and side walls S support anglebrackets 20 which hold the trays 19. A plurality of pipes 18 arearranged to form heating coils through which steam or allied heatingmedium circulatesfthus heating the trays 19 which are supportedthereabove If a-cold circulationv of air is desired, the trays 'may beplaced horizontally as illustrated in Fig. 2, but a more eflicientaction is obtained by sloping the trays ELS IIlHS- trated in Fig. 3. ,v

Thetrays are adapted to contain such fruit or allied material as it isfound advisable to subject to a dry heat. The heatingchamber 15aprovided with a heating coil 15 which lies directly beneath thepartition 12 and heats the air' circulating through the drying chamberwhich flows in the direction indicated by the arrows in Fig. 2. Heatingcoils 21 are arranged at the upper extremity of the drying chamber andextend up within the dehydrating chamber and provide for the maintainingof the drying gases at the proper temperature prior to their contactwith the cool side walls of the dehydrating chamber.

A fresh air inlet pipe 22 is provided and extends below the partition 12and is adapted to supply fresh air to the heating chamber 15. Theadmission of fresh air produces two mutually dependent effects, 6. e.the raising of the humidity of the gases, and the lowering of thetemperature. In order to automatically control the humidity andtemperature of the cabinet, the thermostatic valve T is provided at theentrance of the air inlet pipe and is positioned within the cabinet soas to be subject to the internal temperatures. A gutter or moisturecollecting receptacle 24- extends along the lower portion of themetallic back or plate 8 of the dehydrating chamber and is inclined at aslight angle to the horizontal so that such moisture as is deflectedtherein will drain to one end. A suitable escape is provided for thewater, (not shown) which although allowing for the escapement of water,prevents the ingression of air. However, it is to be understood in thisconnection that the doors 6 are not air-sealed so that there will be nodanger or likelihood of abnormal pressures being produced within theapparatus.

Mention is made of the fact that as illustrated in the drawings, the airflows through the perforations in the pipe 22 during its circulationthroughout the apparatus. However, if desired, a smaller size of pipe 22may be employed, such as illustrated in Fig. t, allowing air to passinto the drying chamber 15 beneath said pipe.

The practical working of the apparatus depends upon the gravitycirculation of dissimilarly heated air, which sets up a forcedcirculation throughout the various chambers and provides for theefficacious drying of such material as may be disposed within the trays19. The hood which forms the dehydrating chamber extends a distanceabove the wooden top 4 of the cabinet and is thus exposed to externaltemperatures which are normally and continuously below the temperatureswithin the cabinet. This provides that the heated and moisture laden airrising or passing through the drying chamber will suddenly contact withthe cooled surface of the hood, with the consequential cooling of theair and precipitation of the moisture. The moisture will collect in thegutter 2i and be led away as described. The rising of the air within thedrying chamber and its falling within the dehydrating chamber causes aconstant circulation of air to be maintained passing through the heatingchamber 15, where it is heated prior to its entrance within the dryingchamber, thus entering the same at the proper temperature. As the airpasses therethrough, it takes up such moisture as may be present withinthe articles disposed in the trays, and the various steam coils withwhich the drying chamber is provided maintain the requisite temperatureof the air despite the evaporation of the moisture.

What is claimed is v 1. A drying cabinet comprising a receptacle, ametallic hood connected to the top and rear walls thereof and extendingthereabove, a partition extending centrally of the hood, a secondpartition abutting the first mentioned partition and dividing the saidreceptacle into communicating drying,

dehydrating, and heating chambers, heating coils disposed within thesaid drying and heating chambers, and automatic thermal controlled meansfor admitting fresh air to the receptacle.

2. A. drying cabinet comprising a receptacle including communicatingdrying, dehydrating, and heating chambers, said dehydrating chamberbeing defined by a metallic hood, means for conducting away the moistureprecipitated upon said hood, heating coils disposed within the saiddrying and heating chambers, means 'for supporting trays above the saidheating coils within the drying chamber, and automatic means forintroducing and controlling the introduction of fresh air within thesaid receptacle.

3. A drying cabinet comprising a receptacle including communicatingdrying, dehydrating, and heating chambers, said dehydrating chamberbeing defined by a metallic'hood, means for conducting away the moistureprecipitated upon said hood, heating coils disposed within the said dry"ing and heating chambers, means for supporting trays above the saidheating coils within the drying chamber, and automatic means forintroducing and controlling the introduction of fresh air within thedrying chamber.

4. A fruit drier comprising a cabinet,

said cabinet including bottom and side 1 walls, a top of relatively lesswidth than the bottom, a metallic hood U-shaped in cross sectionconnected to'the top and bottom walls, a heat insulating partitienextending vertically through the said hood,

a second partition inciined at an to the horizontal, abutting the firstmentioned partition and defining therewith communiill eating heating,drying and dehydrating v chambers, a fresh air inlet pipe located in theniche at the lower extremity of the drying chamber, a thermostatic valvecontrolling the admission of air through said air inlet pipe, heatingcoils disposed within the heating and drying chambers, a moisturecollecting receptacleadjacent the lower ex-' ing parallel to saidmetallic wall and divid-- ing said receptacle into communicating dryingand dehydrating chambers, heating coils dis osed within said dryingchamber, means isposed within the dehydrating chamber adapted to conductaway the moisture precipitated upon the said metallic plate, andautomatic thermally controlled means for admitting fresh air to saidreceptacle.

6. A drying cabinet comprising a receptacle including communicatingdrying, dehydrating, and heating chambers, one external wall of saiddehydrating chamber.

formed of a metallic plate, heating coils disposed within said dryingand heating chambers, and thermally controlled automatic means admittingfresh air to the said rece tacle.

. A drying cabinet comprising a receptacle, a metallic hood connected tothe top and rear walls thereof and extending thereabove, a partitionextending centrally of the hood and formed of material of relatively lowconductivity, saidpartition dividing said receptacle into communicatingdrying and dehydrating compartments, and thermally controlled means forautomatically admitting fresh air to the said recep-.

tacle.

In testimony that I claim the foregoing as my own, I have hereto aflixedmy slgnature in the presence of two witnesses.

' JAMES H. SPRAGUE.

Witnessesz' v I GEORGE G. THIEssEN, JAMES V. LE CLAIR.

